[Enrichment of extracellular DNA from the cultivation medium of human peripheral blood mononuclears with genomic CpG rich fragments results in increased cell production of IL-6 and TNF-a via activation of the NF-kB signaling pathway].

Previously, it was found that blood plasma extracellular DNA (ecDNA) of patients with rheumatoid arthritis (RA) is enriched with CpG-rich genomic DNA fragments, which contain TLR9 ligands (Veiko et al., 2006). In this study we have demonstrated that ecDNA of a RA patient and model fragments added to a cultivation medium of peripheral blood mononuclear cells (PBMC) of healthy donors stimulate expression of genes for the TLR9-MyD88-NF-kB signaling pathway; this leads to a significant increase in concentrations of the proinflammatory cytokines IL-6 and TNF-a in the cultivation medium.

[An IL-6 level in the serum and urine in estimation of cryoglobulinemic vasculitis activity in patients with chronic hepatitis C associated with renal damage].

Aim: To estimate serum and urine IL-6 levels and to study its role in diagnosis of nephritis activity in patients with cryoglobulinemic glomerulonephritis (CGN) associated with chronic hepatitis C (CHC).

Material And Methods: Enzyme immunoassay was used to assay IL-6 in blood serum of 124 patients having different stages of CHC. IL-6 was also estimated in the urine of 57 patients with CHC systemic manifestations including renal damage.

Peripheral blood serum from healthy donors contains antibodies against the fragment of transcribed region of ribosomal repeat.

Enzyme immunoassay showed that blood serum from healthy donors contains specific high-affinity antibodies (apparent association constant > or = 5 x 10(9) M(-1)) against a fragment of transcribed region of ribosomal DNA repeat of human serum, which are present in a free form or are bound to extracellular DNA. Preheating of the serum at 55 degrees C and high ionic strength (1.5 M NaCl) had no effect on the interaction of antibodies with this fragment.

[Ribosomal repeat in the cell free DNA as a marker for cell death].

We have developed a novel method for in vivo evaluation of cell death in patients with acute and/or chronic heart diseases, which are accompanied by apoptosis or cell necrosis. The method is based on the analysis of cell free DNA (cfDNA) in the blood serum (or plasma). The major parameters assessed in the method include total concentration of serum cfDNA, concentration of serum ribosomal repeat (rDNA), content of rDNA in total cfDNA, as well as factors of cfDNA elimination, such as nuclease activity and anti-DNA antibody.

Blood serum DNA in patients with rheumatoid arthritis is considerably enriched with fragments of ribosomal repeats containing immunostimulatory CpG-motifs.

We previously hypothesized that the sequence of transcribed region of human ribosomal repeats is selectively accumulated in circulating extracellular DNA due to its increased resistance to double-strand breaks caused by accumulation of single-chain breaks produced by nucleases. The contents of rDNA in blood serum DNA and in DNA from leukocytic nuclei both in healthy donors and in patients with rheumatoid arthritis were compared using dot hybridization method. By the content of non-methylated CpG-repeats, transcribed region of rDNA is identical to bacterial DNA, which is characterized by potent immunostimulatory effect.